Its time for my 2006 to get a new battery. I know its supposed to use a 90/T5, but I was wondering if anything bigger will fit, while still being compatible with the hold down and the vent tube. The spare tire is not an issue. I'm mainly concerned with getting something with more reserve capacity. An H6 or H7 would be ideal if possible.

 

Someone posted about a red top Optima deep cycle battery and someone else about installing AGM battery.

In here

https://www.chevyhhr.net/forums/gene...ery-hhr-60294/

 

Some group 47 batteries have the vent tube.
Why do you want more "reserve capacity"? 90 minutes is not enough?
Ain't GoOgle great?
https://shop.advanceautoparts.com/r/...ery-size-chart

 

In 10 years of owning the HHR, we put 3 batteries in it. 1 the first week we bought it in the fall of 2014. Duralast Gold. 3 year free replacement then 2 years pro rated. It lasted a little more than 5 years so I bought another in 2020 That one didnt come with same warranty.. 3 years and nothing afterwards. . The 2nd battery up and died in 2024 in August.( 3 years 8 months) Came out to start it and doornail dead. Went with Diehard this time. Same warranty and same price. These small batteries have huge price tags on them. In 10 years I think the price close to doubled. They always had plenty of starting power though.